Our main goal in this application is to determine the conditions under which maternal health literacy predicts some of the observed disparities in participation in public programs designed to improve child health. As delineated in Healthy People 2010, suboptimal child health outcomes remain a persistent problem in the United States and numerous reports have documented under enrollment in public programs known to improve child health (i.e. Medicaid, SCHIP, and food assistance programs). Yet, the mechanisms leading to under enrollment in these programs are not well understood. Children depend on parents to enroll them in programs designed to improve health and low parental health literacy is likely to result in inadequate engagement in these programs, and, ultimately, poor child health outcomes. For example, parents with low literacy may not fully understand enrollment or renewal instructions for public insurance programs such as Medicaid and this may lead to lapses in insurance coverage for their children;in turn, these lapses may lead to delayed immunization. Given that low health literacy is a widespread problem that affects more than 90 million American adults (~20 percent of the adult population), many children have parents with inadequate health literacy. Prior studies have shown that low health literacy results in inadequate engagement in health care and that low health literacy is likely to be a major contributor of adverse health outcomes in adults. Examining the relationship between maternal health literacy and participation in public programs designed to improve child health may provide evidence to suggest changes in enrollment procedures that could help improve child participation rates in these programs, and, ultimately, child health. An exploratory analysis of the extent to which participation in public programs reduces or eliminates the association between low maternal health literacy and poor child health outcomes will also be conducted. To achieve these aims, an expanded data analysis of subjects in an ongoing three-year longitudinal cohort study will be conducted by combining data from surveys, administrative Medicaid eligibility files, CHOP's state-of-the-art electronic medical record, and Philadelphia's electronic immunization registry. The results of the proposed study will provide critical data for the development of interventions to improve participation in public programs designed to improve child health and, ultimately, reduce disparities in child health outcomes. Public Health Relevance: Under enrollment in public programs designed to improve child health is a persistent and intractable problem in the United States. In this project, we examine the influence of maternal health literacy on participation in child health programs because low health literacy is a widespread problem. These results may provide evidence to suggest changes in enrollment procedures that could help improve child participation rates in these programs, and, ultimately, child health.